Note: Descriptions are shown in the official language in which they were submitted.
The invention relates to a boat slipway for mobile -
or fixed arrangement, comprising a framework and provided
thereon supporting means for a boat, which framework may
be in an almost horizontal position when a boat is support-
ed thereby and which may be swung into an inclined position
for facilitating the launching of a boat from the slipway
in-to the water or vice versa.
Similar devices, which are usually of the mobile
type, are used at a large scale for the transportation
of boats behind motor vehicles.
With these ]cnown, so-called "slipway trailers"
the pole, which can be connected with the towing hook of
a motor vehicle, is hinged to a point of the framework,
which is provided at some distance from the front end of
the framework. When the slipway is put into an inclined
posi~ion, the front end of the framework can thereby move
upwards with respect to the pole, and this upwards move-
ment may be controlled e.g. by means of a threaded rod.The inclination to which the framework can be moved,
is relatively small, inter alia because in general the
trailer will have to remain connected with the towing
hook because of the stability of the trailer when the
boat is launched. For that reason the pole is not
allowed to form too great an angle with the horizontal
as that would mean too great a load on the hinge of the
towing hook.
For these reasons such a device can be used only
when launching a boat and taking it out of the water
one has the use of a gradually sloping bank at an angle
of which the variation must be small. When the slope is
too small, the motor vehicle will have to be driven too
far into the water to make the boat float
- 2 -
whereas in the case of a -too steep slope a motor vehicle of a
heavy weight will have to be available.
With such a slipway trailer the framework will pivot
around the supporting point wherein the axle and the wheels are
provided. When this axle is arranged fixed on the shore, a very
long framework will be necessary which will have to be of a
very heavy construc-tion to offer resistance to the high hending
loads when a boat is launched or taken out of the water.
According to the present invention, there is provided
a mobile or fixed boat slipway apparatus, comprising a frame-
work having means for supporting a boat, said framework support-
ed for pivotal movement between a substantially horizontal posi-
tion when a boat is supported thereby and an inclined position
for facilitating the launching or landing a boat from the slipway
into and out of the water, said framework mounted to be freely
pivotable around a support shaft and including a slide mounted
for telescopic movement in a longitudianl direction along the
length of said framework, said telescopic slide havlng an outer
end portion which is projectable outwardly from the framework,
at least one buoyant element for supporting said end portion of
said slide from the water, and means for selectively adjusting
the buoyant force of said element so that said end portion of
said slide may be submerged in the water when a boat is launched
or taken out of the water, said slide including means supporting
an undercarriage for a boat mounted to travel longitudinally
along said framework in telescopic relation thereto, said under-
carriage supported on said framework by means of at least two
pairs of spaced apart flanged rollers for guiding said undercar-
riage against substantial lateral deflection with respect to
said framework, said undercarriage and said framework including
means for restraining said undercarriage against displacement
normal and away from said framework during telescopic movement
thereon.
` ~ 3 -
~ ~ ti'~
The present invention overcomes the above drawbacks by
providing a boat slipway, in which the framework can freely hinge
around a shaft and comprises at least one part which is telescop-
ic in the longitudinal direction ofthe framework, which tele-
scopic part is provided adjacent its end which extends from the
framework with means for connecting the framework with at least
one floating body, such that the end of the framework, even under
maximum load, can be maintained floating on the water, and means
are provided for adjusting the buoyancy of the floating body,
such that the end of the framework can be located under the
surface of the water when a boat is launched or taken out of
the water.
Thus the framework acts as a supporting beam, which is
supported adjacent its ends, when a boat is launched or taken
out of the water. Thus the bending moments exerted on the frame-
work can be kept small, so that the framework may be of a light-
weight construction.
According to a further embodiment of the invention, the
boat is located on an undercarriage which can move over the
framework
- 3a -
and the telescopic part thereof.
Thus the position of the boat with respect to the
slipway can easily be adjusted somewhat for a very
gradual displacement of the centre of gravity of the boat
with slipway with respect to the shaft, around which -the
framework can hinge.
With a boat trailer it is desirable, e.g. that
the pole rests with a certain force on the towing hook,
so that during the ride the boat must be placed on a very
particular place of the framework and must be secured in
this position. When the telescopic parts of the framework
are extended, the weight of these parts may cause the
framework to hinge around the hinging shaft before the
telescopic part is extended entirely. This can be easily
prevented by moving the undercarriage, on which the boat
is placed somewhat to the front in the direction of the
towing hook, so that the whole remains balanced. After
~0 the telescopic part of the framework has been extended
entirely and blocked, the undercarriage is moved in the
opposite direction, towards the -telescopic part, so that
the entire framework with the boat will hinge gradually
until the floating body rests on the water. Then the
undercarriage with the boat is moved adjacent the end
of the extended telescopic part and the buoyancy of the
floating body is gradually reduced, so that the end of
the framework sinks below the water surface and the boat
is freed from the undercarriage. Final]y the connection
between the boat and the highest point of the under-
carriage is released to free the boat completely from
the undercarriage.
An important advantage of the use of an under- ~
carriage on which the boat rests, is that the boat does
not need to be displaced over rollers which might exert
a considerable load on the hull of the boat, as the shape
of the hull changes considerably over its length so that
the rollers which first lie against walls that form a
certain angle, will later lie against walls that form
another angle with one another. When a boat is drawn
onto a boat trailer, considerable loads are therefore
10 exerted normally on the walls of the hull and therefore
also on the construction by which the rollers are sup-
ported. This is avoided with the slipway according to
the present invention, with which the boat can be sup-
ported at the places which are most suitable and which
15 can be preselected. This will preferably be places at
which there is a truss of the boat.
According to a preferable embodiment the under-
carriage can travel over the framework by means of at
20 least four rollers mounted in two pairs one behind the
other, provided with flanges for guiding the undercarriage
in the lateral direction with respect to the framework,
whereas the undercarriage is further provided with means
which extend downwards from the undercarriage and have a
25 part which is bent inwardly and partly encloses the frame-
work so as to retain the undercarriage also in the vertical
direction with respect to the framework and -the telescopic
part thereof.
The means which hold the undercarriage in the
vertical direction, may be provided near the rollers, but
it is also possible to provide only one means at each
side of tne undercarriage, approximately between two rollers
provided at that side. Thus the undercarriage is restrain-
-- 5
A. ~
ed from starting to turn over with respect to the one
set of wheels when a part of the boat, which rests on
the undercarriage, starts to float.
Accordiny to another prefexable embodiment,
two floating bodies are provided, one at each side of the
telescopic part of the framework. Thus a certain lateral
stability of also the part of the framework which floats
on the water, will be assured. Furthermore this reduces
the risk of the boat contacting a floating body when it is
launched or taken out of the water.
Inflatable air bags can be used as floating
bodles. They can be inflated e.g. by means of an air
pump which is driven by means of the battery of a motor
vehicle. It is also possible to use the exhaust gas
of the vehicle or other gases, such as pressurized gases
available on the market.
It is also possible to use floating bodies with
rigid walls in which case one can let water into the
floating bodies and press this water out by means of
compressed air.
When inflatable air bags are used, each air
bag can be secured to the top side of a horizontal
framework which by means of one or more eyele-ts can be
slid on a shaft which extend laterally from the telescopic
part of the framework. In this way the air bags can be
30 mounted easily on the framework and be removed after their
use, during the`transportation of the device. A further
advantage is that the air bag can always turn to the most
favourable position with respect to the water surface,
whatever the angle of the framework to the water surface
35 may be. The laterally projecting shaft can be fixedly
or pivotably connected to the telescopic part such that
it will give no difficulties during the transport oE the
boat slipway.
According to a still further preferable embodiment
the framework comprises a pair of U-profiles, of which the
legs extend towards each other, and of which at least two
opposing legs are connected with each other, whereas
parts of the telescopic framework are accommodated in the
two U-proflles. Thus a stable construction is obtained
which requires little height.
According to a further embodiment of the inven-
tion the telescopic part of the framework comprises a
tubular profiles, preferably with a rectangular cross
section, mounted lengthwise, which are connec-ted with
each other by means of strips, which are spaced at a
distance from each other, that they form the rungs of
a ladder, while also the end of the framework adjacent the
telescopic section is provided with these rungs.
In this way an easy access is obtained to the
boat when it has to be launched or taken out of the water
by means of the slipway.
Although in the above mainly the slipway according
to the invention in the form of a boat trailer was dis-
cussed, which therefore can be transported behind a motor
vehicle, the boat slipway can be used also without a
set of wheels. In that case the hinging shaft is secured
to the ground by means of a supporting construction.
Such a possibility is of great importance to
boat owners who do have the disposal of ground adjacent
to a waterway, but who are not allowed to build a land-
ing stage or even moor their boat there.
~,_ 7 _
They can now set up a construction according tothe invention on their own ground, so that they can easily
launch the boat from their own ground and take it out
of the water after having used it.
Such a possibility exists of course also for
wharves for boats where a device according to the inven--
tion can be used for launching
- 7a -
1'7
-- 8
boats and taking them out of the water. Such a wharf may then be
locate~ atcln.lrrc~ waterway/ as onl~ a part of the waterway wlll be
obstructed for only a short tlme, namely when boats are launched
or taken out of the water.
At such a wharf the und~rcarrlage used for launching boats and
taklng them out of the water, can be carried out in such a way
that lt can be drlven from tlle slipway onto the shore, so that the
boat remalns on the same carriage during repalrs or storage.
So lt ls posslble to use one single slipway for a large numbcr
of boats.
The lnventlon will be explained herelnafter by means of nn
example of an embodiment shown in the drawing, in which:
~ igure 1 shows a lateral view of a moblle boat slipway accorcl-
lng to the present invention, in the position in which the teles-
copic part of the framework ls extended and by means of the Eloatln~
bodies rests on a water surface as ls the case when a boat is bcin~
launc!l~d or af-er it has been taken out of the water;
~ lgure 2 shows a lateral vlew of the device according to 1~1-
gure 1, in whlch the framework is in its horizontal position nnd
the telescopic part is extended only slightly, whereas there is
no boat on the undercarriage;
Figure 3 glves a top view of the frame work, with the teles-
copic part and a part of the undercarriage travelling tilereon, as
shown in figure 2;
Figure 4 shows a cross sectlon of the frame work, the part
whlch ls telescopic thereJn and the unclercarriage travelllng there-
on, approximately along the llne IV-IV of figure 2;
Figure 5 shows a rear view of the lower par~ of
the device as shown in ~i~ure 1, and
Flgure 6 gives a perSpective view from below
of a framework and a floating body mounted thereto.
The device shown in the drawing comprises the
chassis 1, which is supported by the set of wheels 2,
the auxiliary wheel 3 and the coupling 4. The coupling
4 can be connected with the towing hook (not shown) of
a vehicle.
The chassis 1 further comprises a hinging shaft
5, which serves for the hinging support of the framework
6, which is provided with a telescopic part 7. Over the
framework 6 and the telescopic part 7 thereof can travel
the undercarriage 8, on which the boat 10 is supported
by means of supports 9.
To the free end of the telescopic parts 7 can be
mounted floating bodies 11, as i9 shown in particular
in Figure 1.
As is shown in Figures 3 and 4, the framework
6 consists of the U-profiles 12, which are connected
with each other at the one end by means of a profile
13 and furthermore by means of strips 14. At the place
where the hinging point is- provided, such a strip of
heavy structure is provided with eyelets 15 for accom-
modating the hinging shaft 5 (see Figure 2).
Within the U-profiles 12 of the framework 6 is
provided the telescopic part 7, which consists of two
longitudinal tubular profiles 16, which are connected wi-th
each other by means of rods 17. As is shown in Figure 3,
the rods 17 may form the rungs of a ladder.
~_ g _
l t~ 7
At their outward end, the tubular profiles 16
are connected with each other by ~eans of a profile 18,
on which the rods 19 are
- 9a -
gt,~
- 10 --
provided, s~Fig. 5. On the rods 19 the eyelets 20 (see figure 6)
can be slid~ whlch are connected with a frame~ork 21, on which an
alr bag 22 ls provlded by means of a net 23, ~or securing a frame-
wor~ 21 on a rod 19, e.g, this rod 19 may have a threaded end on
which a nut 24 can be tightened. J ~ /ec~e~
The telescoplc part 7 can be secured at a~~crtain place in
the framework 6, e.g. by means of a pin construction. It is obvio~-s
furthermore, that cams will be provided for preventing the teles-
coplc part 7 from belng drawn out of the framewor~ 6, whereas it
is assured that thetelesco~ic part 7 is always supported over a
certaln length by the framework 6.
~ s shown in flgures 2 and 3, the undercarriage 8 consists
of two longitudlnal tubular profiles 26, which at their ends are
connected with each other by the profiles 27.
From the tubular profiles 26 project the proEiles 2~ (see
also figure 2! whlch ~ay be connected with eacll other by means
of profiles 29 and which may approach each other at the ends whlch
are not wlthin the tubular profiles 26 and are connectcd there b~
thc support 30.
The support 30 may be of the known telescGplc construction,
so that the V-shaped boat support 31, which is provided at the
upper end, can be set atthe deslred helght. The support 30 ls
provided further with the eyelet 32 to tie a boat 1n a known way
to the support 30.
It will be obvlous that the place of the support 30, seen ir
the lo~ltudlnal direction oE the undercarriage, can be adapted
to thc lengtll of the boat by more or less movin~J the profiles 2
out of the profiles 26. Once the right ]ength has been set, the
profiles 28 can be secured with respect to the profiles
26 in a known, not shown way.
Each of the profiles 26 is provided with two
shafts 33 (Figure 4), on the each of which a wheel 34 is
provided. By means of the wheels 34 the undercarriage can
travel over the framework 6 and over the telescopic part
7 thereof.
To prevent the undercarriage freeing itself from
the framework 6 or from the telescopic part 7, square
supports 35 are provided on the sides of the undercarriage,
which extend around the U-profiles 12 and are provided
at their underside wi,th a shaft 36 on which a roller 37
is provided.
For the sake of clearness, Figure 4 only shows one
of these supports 35. It will be obvious that such sup-
ports may be provided at the~front and rear ends of the
undercarriage, but it is also possible to provide at each
side of the undercarriage only one support 35, which will
then be provided approximately in the middle between
two wheels 34.
The travel of the undercarriage takes place by
means of a manually operated winch 38, on which a cable
39 can be wound, which runs over a pulley 40 provided
on the profile 13 of the frameworX 6 and from there to
the fixation point 41 on a profile 27 of the undercarriage
8.
Finally the chassis 1 is provided with a dis-
placeable support 42, so that during transportation the
support 30 or the boat 10 can'be oonnected directly with
the chassis 1.
'7
The device works as follows: -~
After the chassis 1 supported by the wheels 2 has
been towed to a selected place on the bank, the auxiliary
wheel 3 is lowered to prevent too great a downward force
on the towing hook of the -towing vehicle.
After the COnnectiQn between the boat 10 or the
support 32 and the support 42 of the chassis 1 has been
released, the telescopic part 7 is drawn out of the
framework 6. The floating bodies 11, shown in figure 6,
are now secured to the rods 19, as shown in Figure 5.
When the telescopic part 7 is drawn out, the
centre of gravity of the combination, hinging around the
shaft 5, is displaced to the left, as seen in Figure 1,
so that the r-isk exists that the whole combination
will hinge to the l~ft too quickly. In order to prevent
this, the undercarriage 8 is drawn slightly to the front
and so upwardly, as seen in Figure 1, by means of winch
38.
In the extended position thereof the part 7 is
secured to the framework 6, e.g. by means of pins, and
the chassis 1 may be moved further backwards to the bank.
In the position of the chassis 1, as shown approximately
in Figure 1, the cable 39 is let out by the winch 38, so
that the undercarriage starts to trave] backwards slowly
and the whole combination starts to hinge around the
shaft 5 until the floating bodies 11 are in the water, as
shown in Figure 1.
Now the undercarriage 8 is allowed to travel fur~
ther downwards over the framework 6 and the part 7 until
a certain moment the stern of the boat 10 enters the water
and the boat 10 starts to float to a large extent
- 12 -
on the water. Then -the buoyancy of the floating bodies
11 is reduced, so that the whole combination of framework
6 and telescopic part 7 still further hinges to the left,
as seen in Figure 1, so that the free end of the tele-
scopic part 7 hinges further away from the boat and theboat lies entirely free in the water. Then the connection
between the boat and the support 30 is released.
The boat can move away and subsequently the empty
undercarriage 8 is drawn up by means of the winch 38 and
the cable 39. The telescopic part 7 is slid into the
framework 6, the floating bodies 11 are removed, after
which approximately the position as shown in Figure 2,
is reached.
To take the boat out of the water and back on
the undercarriage, the procedure is reversed, so that
first the buoyancy of the floating bodies 11 is as small
as possible when the empty undercarriage is taken down,
whereas after the connection between the undercarriage
and the boat has been established, the buoyancy of the
floating bodies 11 is increased to take -the boat out
of the water, at least at its front end.
As e~plained above, it is possible when the
floating bodies 11 are carried out in the way as shown
in Figure 6 that buoyancy is obtained by pumping air
into the air bags 22, whereas the buoyancy can be reduced
by emptying the air bags. By connec-ting the bags 22
with hoses running to an air pump set up near the motor
vehicle or to the exhaust pipe of the vehicle, it is pos-
sible to adjust the buoyancy from ashore, by means of
e.g. a control valve or a three-way tap.
As said above, the hinging shaft 5 may also be
mounted on a fixed support on the bank, in which case
- 13 -
4~L7
it will of course be necessary to proyide supports for --
the front end of the framework 6 in approximately
its hori~ontal position.
When it is required that no parts project beyond
the bank when the boat is on -the shore, the hinging
shaft 5 may be mounted on an approximately horizontally
mobile slide. The displacement of the slide can take
place e.g. by means o a winch and a somewhat oblique
position of -the slide, as has been described for the
travelling of the undercarriage 8.
When there is enough free space at the bank
use can be made of a telescopic part 7 of great length
which is slidably supported by a short framework 6, in
such a way that the undercarriage 8 is always supported
by the telescopic part. The landward directed end of the
telescopic part can be provided with wheels, supported
by the ground as long as the other end of the telescopic
part is not being swung to the water. In this case,
generally speaking, no displacement of, the pivoting
shaft of the framework will be necessary.
Furthermore it will be obvious that mechanical
means can be used for the displacement of the telescopic
part 7 of the framework 6 as well. This will be espec-
ially the case when the device is carr,ed out heavily,
e.g. for use at a shipyard.
It is further pointed out that the-telescopic
part can be separated into two parts, so that a telescopic
construction is obtained with which even greater hori-
zontal and/or vertical distances can be covered.
- 14 -
- ~5 -
Page 6 line 12 :
1 It is also possible to use the exhaust gas
of the vehicle or o-ther gasses such as
pressuri~ed gasses available on the market.
age 6 line 24 :
2 The laterally pro]ecting shaft can be fixedly
or pivotably connected to the telescopic part
such that it will yive ~ difficulties during
the transport of the boat s].ipway
